U.S. patent application number 17/155622 was filed with the patent office on 2021-07-29 for vehicle behavior control device and vehicle behavior control method.
The applicant listed for this patent is HONDA MOTOR CO., LTD.. Invention is credited to Kenji KOMORI, Shinsuke ODAI.
Application Number | 20210229642 17/155622 |
Document ID | / |
Family ID | 1000005389128 |
Filed Date | 2021-07-29 |
United States Patent
Application |
20210229642 |
Kind Code |
A1 |
KOMORI; Kenji ; et
al. |
July 29, 2021 |
VEHICLE BEHAVIOR CONTROL DEVICE AND VEHICLE BEHAVIOR CONTROL
METHOD
Abstract
A vehicle behavior control device is equipped with an other
vehicle detection unit that detects another vehicle, a collision
prediction unit that predicts that the other vehicle will collide
with a side surface of a user's own vehicle, a physical quantity
determination unit that determines a physical quantity relationship
between relative physical quantities of the other vehicle and the
user's own vehicle, and a brake control unit that is capable of
individually and independently controlling brakes corresponding to
respective vehicle wheels and that causes a braking force of the
brakes on a collision side and a braking force of the brakes on a
non-collision side to differ from each other, in accordance with
the physical quantity relationship determined by the physical
quantity determination unit, in the case that a collision is
predicted by the collision prediction unit.
Inventors: |
KOMORI; Kenji; (WAKO-SHI,
JP) ; ODAI; Shinsuke; (WAKO-SHI, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HONDA MOTOR CO., LTD. |
TOKYO |
|
JP |
|
|
Family ID: |
1000005389128 |
Appl. No.: |
17/155622 |
Filed: |
January 22, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G08G 1/16 20130101; B60T
2230/03 20130101; B60T 8/241 20130101; B60T 7/22 20130101; B60T
8/17 20130101; B60T 2250/00 20130101; B60T 2201/024 20130101 |
International
Class: |
B60T 7/22 20060101
B60T007/22; G08G 1/16 20060101 G08G001/16; B60T 8/17 20060101
B60T008/17; B60T 8/24 20060101 B60T008/24 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 27, 2020 |
JP |
2020-010519 |
Claims
1. A vehicle behavior control device that controls a behavior of a
vehicle when another vehicle is predicted to collide with a side
surface of the vehicle, the vehicle behavior control device
comprising: an other vehicle detection unit configured to detect
the another vehicle; a collision prediction unit configured to
predict that the another vehicle will collide with the side surface
of the vehicle; a physical quantity determination unit configured
to determine a physical quantity relationship between relative
physical quantities of the another vehicle and the vehicle; and a
brake control unit configured to individually and independently
control brakes corresponding to respective vehicle wheels, and to
cause a braking force of the brakes on a collision side and a
braking force of the brakes on a non-collision side to differ from
each other, in accordance with the physical quantity relationship
determined by the physical quantity determination unit, in a case
that a collision is predicted by the collision prediction unit.
2. The vehicle behavior control device according to claim 1,
wherein: the collision prediction unit predicts a time of the
collision of the another vehicle with the side surface of the
vehicle; and in a case that the physical quantity determination
unit determines that the physical quantity of the another vehicle
is less than the physical quantity of the vehicle, the brake
control unit makes the braking force of the brakes on the collision
side greater than the braking force of the brakes on the
non-collision side at a predetermined time prior to the time of the
collision, and makes the braking force of the brakes on the
non-collision side greater than the braking force of the brakes on
the collision side after the collision.
3. The vehicle behavior control device according to claim 1,
wherein: the collision prediction unit predicts a time of the
collision of the another vehicle with the side surface of the
vehicle; and in a case that the physical quantity determination
unit determines that the physical quantity of the another vehicle
is greater than the physical quantity of the vehicle, the brake
control unit makes the braking force of the brakes on the
non-collision side greater than the braking force of the brakes on
the collision side at a predetermined time prior to the time of the
collision.
4. The vehicle behavior control device according to claim 1,
further comprising a posture determination unit configured to
determine a posture of the vehicle, wherein, after the collision,
the brake control unit performs a control to cause the braking
force of the brakes on the collision side and the braking force of
the brakes on the non-collision side to differ from each other, and
thereafter, switches a strength of the braking force of the brakes
between the collision side and the non-collision side in accordance
with the posture of the vehicle determined by the posture
determination unit.
5. The vehicle behavior control device according to claim 4,
wherein: the posture determination unit determines whether or not a
roll direction of the vehicle has changed; and in a case that the
posture determination unit determines that the roll direction has
changed, the brake control unit switches the strength of the
braking force of the brakes between the collision side and the
non-collision side.
6. A vehicle behavior control method of controlling, using a
processor, a behavior of a vehicle when another vehicle is
predicted to collide with a side surface of the vehicle, wherein
brakes corresponding to respective vehicle wheels are allowed to be
individually and independently controlled, the vehicle behavior
control method comprising: an other vehicle detecting step of
detecting the another vehicle; a collision predicting step of
predicting that the another vehicle will collide with the side
surface of the vehicle; a physical quantity determination step of
determining a physical quantity relationship between relative
physical quantities of the another vehicle and the vehicle; and a
brake controlling step of causing a braking force of the brakes on
a collision side and a braking force of the brakes on a
non-collision side to differ from each other, in accordance with
the physical quantity relationship determined in the physical
quantity determination step, in a case that a collision is
predicted in the collision predicting step.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2020-010519 filed on
Jan. 27, 2020, the contents of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates to a vehicle behavior control
device and a vehicle behavior control method, which control the
behavior of a user's own vehicle when another vehicle is predicted
to collide with a side surface of the user's own vehicle.
Description of the Related Art
[0003] In Japanese Laid-Open Patent Publication No. 2005-254944, a
device is disclosed that reduces a load applied to a vehicle body
on a side where a collision takes place, in the case that another
vehicle has collided (a side collision has occurred) with a side
surface of the user's own vehicle. In such a device, a predicted
time of the side collision and a predicted position (front portion,
middle portion, rear portion) of the side collision are calculated.
In addition, the device selects either the front wheel or the rear
wheel on a side where the collision does not occur based on the
predicted position of the side collision, and in a period from a
predetermined time prior to the predicted time of the side
collision and until an acceleration of the vehicle body becomes
less than or equal to a predetermined value, forcibly controls the
braking force of the selected wheel so as to become higher than the
braking force of the other wheels.
SUMMARY OF THE INVENTION
[0004] In the device of Japanese Laid-Open Patent Publication No.
2005-254944, the load applied to the vehicle body due to a yaw
motion being generated in the case that the other vehicle collides
with the side surface of the user's own vehicle is reduced. On the
other hand, the device of Japanese Laid-Open Patent Publication No.
2005-254944 does nothing to stabilize the behavior of the vehicle
in a roll direction.
[0005] Further, in the device of Japanese Laid-Open Patent
Publication No. 2005-254944, there is a requirement to precisely
control the braking forces of four brakes, and thus the control is
complicated.
[0006] The present invention has been devised taking into
consideration the aforementioned problems, and has the object of
providing a vehicle behavior control device and a vehicle behavior
control method, in which with a simple control, it is possible to
stabilize the behavior of a user's own vehicle in a roll direction,
in the case that another vehicle collides with a side surface of
the user's own vehicle.
[0007] A first aspect of the present invention is characterized by
a vehicle behavior control device that controls a behavior of a
vehicle when another vehicle is predicted to collide with a side
surface of the vehicle, the vehicle behavior control device
comprising:
[0008] an other vehicle detection unit configured to detect the
another vehicle;
[0009] a collision prediction unit configured to predict that the
another vehicle will collide with the side surface of the
vehicle;
[0010] a physical quantity determination unit configured to
determine a physical quantity relationship between relative
physical quantities of the another vehicle and the vehicle; and
[0011] a brake control unit configured to individually and
independently control brakes corresponding to respective vehicle
wheels, and to cause a braking force of the brakes on a collision
side and a braking force of the brakes on a non-collision side to
differ from each other, in accordance with the physical quantity
relationship determined by the physical quantity determination
unit, in a case that a collision is predicted by the collision
prediction unit.
[0012] A second aspect of the present invention is characterized by
a vehicle behavior control method of controlling, using a
processor, a behavior of a vehicle when another vehicle is
predicted to collide with a side surface of the vehicle, wherein
brakes corresponding to respective vehicle wheels are allowed to be
individually and independently controlled,
[0013] the vehicle behavior control method comprising:
[0014] an other vehicle detecting step of detecting the another
vehicle;
[0015] a collision predicting step of predicting that the another
vehicle will collide with the side surface of the vehicle;
[0016] a physical quantity determination step of determining a
physical quantity relationship between relative physical quantities
of the another vehicle and the vehicle; and
[0017] a brake controlling step of causing a braking force of the
brakes on a collision side and a braking force of the brakes on a
non-collision side to differ from each other, in accordance with
the physical quantity relationship determined in the physical
quantity determination step, in a case that a collision is
predicted in the collision predicting step.
[0018] According to the present invention, with a simple control,
it is possible to stabilize the behavior of the vehicle in the roll
direction, in the case that another vehicle collides with a side
surface of the vehicle.
[0019] The above and other objects, features, and advantages of the
present invention will become more apparent from the following
description when taken in conjunction with the accompanying
drawings, in which preferred embodiments of the present invention
are shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a diagram showing the configuration of a vehicle
behavior control device according to a first embodiment;
[0021] FIGS. 2A, 2B, 2C, 2D, 2E, and 2F are views showing six
scenarios before and after a collision of another vehicle having a
lower vehicle height on a right side surface of a user's own
vehicle, along with operating states of the brakes in each of the
scenarios;
[0022] FIGS. 3A, 3B, 3C, 3D, 3E, and 3F are views showing six
scenarios before and after a collision of another vehicle having a
higher vehicle height on a right side surface of a user's own
vehicle, along with operating states of the brakes in each of the
scenarios;
[0023] FIG. 4 is a flowchart showing the process flow of a vehicle
behavior control; and
[0024] FIG. 5 is a diagram showing the configuration of a vehicle
behavior control device according to a second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] Preferred embodiments of a vehicle behavior control device
and a vehicle behavior control method according to the present
invention will be presented and described in detail below with
reference to the accompanying drawings.
1. First Embodiment
1.1. Configuration of Vehicle Behavior Control Device 10
[0026] As shown in FIG. 1, the vehicle behavior control device 10
is disposed in a user's own vehicle 80 (see FIGS. 2A to 2F, etc.),
and is equipped with an ON/OFF switch 12, a sensor group 14, a
brake ECU 16, and a brake system 18.
[0027] The ON/OFF switch 12 is a user interface provided in the
interior of the vehicle. The ON/OFF switch 12 outputs to the brake
ECU 16 an operation start command in response to an ON operation
performed by a vehicle occupant, and outputs to the brake ECU 16 an
operation stop command in response to an OFF operation performed by
the vehicle occupant.
[0028] In the sensor group 14, there are included cameras 22, an
acceleration sensor 24, wheel speed sensors 26, and a steering
angle sensor 27. One or more cameras 22 are provided respectively
on each of the left and right sides of the user's own vehicle 80.
By the one or more cameras 22 provided on the right side of the
user's own vehicle 80, images are captured of the right front
direction, the right center direction, and the right rear direction
of the user's own vehicle 80. Similarly, by the one or more cameras
22 provided on the left side of the user's own vehicle 80, images
are captured of the left front direction, the left center
direction, and the left rear direction of the user's own vehicle
80. The cameras 22 output captured image information to the brake
ECU 16. Moreover, instead of the cameras 22, sensing devices such
as radar devices, LiDAR devices, or SONAR devices may be provided.
The acceleration sensor 24 measures acceleration (including
deceleration) in three directions of the XYZ axes (a roll axis, a
pitch axis, and a yaw axis). The acceleration sensor 24 outputs
information of the measured acceleration to the brake ECU 16. The
wheel speed sensors 26 are provided corresponding to each of the
vehicle wheels of the user's own vehicle 80. The wheel speed
sensors 26 output information of the measured wheel speeds to the
brake ECU 16. The steering angle sensor 27 measures a steering
angle (an operating angle of the steering wheel or a steering angle
of the vehicle wheels). The steering angle sensor 27 outputs
information of the measured steering angle to the brake ECU 16.
[0029] The brake ECU 16 includes an input/output unit 28, a
computation unit 30, and a storage unit 32. The input/output unit
28 is constituted by an A/D conversion circuit, a communication
interface, a driver, and the like. The computation unit 30 is
constituted from a processor equipped with, for example, a CPU or
the like. The computation unit 30 realizes various functions by
executing programs stored in the storage unit 32. In the present
embodiment, the computation unit 30 functions as an other vehicle
detection unit 34, a collision prediction unit 36, a physical
quantity determination unit 38, a brake control unit 40, a
collision detection unit 42, and a posture determination unit
44.
[0030] The other vehicle detection unit 34 detects another vehicle
90 by carrying out image recognition using the image information
captured by the cameras 22. The collision prediction unit 36
predicts that the other vehicle 90 will collide with a side surface
82 of the user's own vehicle 80 (see FIGS. 2A to 2F, etc.), based
on the detection result of the other vehicle detection unit 34, and
the wheel speeds (vehicle speed) measured by the wheel speed
sensors 26. The physical quantity determination unit 38 determines
a physical quantity relationship between relative physical
quantities of the other vehicle 90 and the user's own vehicle 80,
based on the detection result of the other vehicle detection unit
34, and vehicle information that is stored by the storage unit 32.
The physical quantity, for example, is a vehicle height, a volume,
a weight, or the like. The physical quantity which is used in the
present embodiment is the vehicle height. The brake control unit 40
controls each of the brakes independently, by outputting command
signals to each of the brakes of the brake system 18. In the case
that a collision is predicted by the collision prediction unit 36,
the brake control unit 40 performs a control to cause the braking
force of the brakes on a collision side and a braking force of the
brakes on a non-collision side to differ from each other, in
accordance with the physical quantity relationship determined by
the physical quantity determination unit 38. The collision
detection unit 42 detects collision of the other vehicle 90 with
the side surface 82 of the user's own vehicle 80 (see FIGS. 2A to
2F, etc.), based on the acceleration measured by the acceleration
sensor 24. The posture determination unit 44 determines the posture
of the user's own vehicle 80, based on the acceleration measured by
the acceleration sensor 24.
[0031] The storage unit 32 is constituted by a RAM and a ROM or the
like. The storage unit 32 stores, in addition to various programs,
various information used by processes of the computation unit 30.
In this instance, the storage unit 32 stores vehicle information
for the user's own vehicle 80. The vehicle information includes
information indicating the physical quantity of the user's own
vehicle 80. Further, in the vehicle information, there may be
included information that links the vehicle type of the other
vehicle 90, the characteristics of the external appearance of such
a vehicle type, and the physical quantity of such a vehicle
type.
[0032] The brake system 18 includes four brakes, and more
specifically, a right front brake unit 46RF, a right rear brake
unit 46RR, a left front brake unit 46LF, and a left rear brake unit
46LR, which apply braking to the respective vehicle wheels, in this
case four wheels. Each of the brakes applies braking to its
corresponding wheel in response to a command signal output from the
brake ECU 16.
1.2. Transitioning of Brake Control at the Time of a Side
Collision
[0033] Transitioning of the brake control performed by the vehicle
behavior control device 10 before and after a side collision has
taken place will be described with reference to FIGS. 2A to 2F and
FIGS. 3A to 3F. Moreover, in FIGS. 2A to 2F and FIGS. 3A to 3F, the
left-right direction of the paper surface corresponds to a
left-right direction of the user's own vehicle 80, the rearward
(inward) direction of the paper surface corresponds to a frontward
direction of the user's own vehicle 80, and a frontward (outward)
direction of the paper surface corresponds to a rearward direction
of the user's own vehicle 80.
[0034] Further, in FIGS. 2A to 2F and FIGS. 3A to 3F, among right
wheels 84R (front and rear wheels on the right side) and left
wheels 84L (front and rear wheels on the left side), the front and
rear wheels on a side subjected to strong braking are shown by
hatching.
[0035] In the following description, among the left and right sides
of the user's own vehicle 80, a direction of the side surface 82
for which it is predicted that a collision will occur, and a
direction of the side surface 82 where the collision has occurred
are referred to as a "collision side". Further, among the left and
right sides of the user's own vehicle 80, a direction of the side
surface 82 for which it is not predicted that a collision will
occur, and a direction of the side surface 82 where the collision
has not occurred are referred to as a "non-collision side". In the
examples shown in FIGS. 2A to 2F and FIGS. 3A to 3F, the right side
is the collision side, and the left side is the non-collision
side.
2.1. Situation in which Other Vehicle 90 Having a Lower Vehicle
Height Collides with Side Surface 82 of User's Own Vehicle 80
[0036] In the case that the vehicle height of the other vehicle 90
is lower than the vehicle height of the user's own vehicle 80, the
brake control unit 40 causes the operating state of the brakes to
undergo a transition as shown in FIGS. 2A to 2F.
[0037] FIG. 2A shows states of the user's own vehicle 80 and the
other vehicle 90 when the time to collision (hereinafter referred
to as a TTC) has become less than or equal to a predetermined
control starting time period. At this time, the brake control unit
40 generates a braking force for the brakes on the right side,
which is the collision side, in particular, the right front brake
unit 46RF and the right rear brake unit 46RR. Upon doing so, the
right wheels 84R are subjected to braking. At this time, the brake
control unit 40 may generate a braking force for the brakes on the
left side, which is the non-collision side, in particular, the left
front brake unit 46LF and the left rear brake unit 46LR. However,
in the case that the braking force of the brakes on the left side
is generated, the brake control unit 40 makes the braking force of
the brakes on the left side weaker than the braking force of the
brakes on the right side. Due to the control performed by the brake
control unit 40, the user's own vehicle 80 becomes inclined in a
sunken-in manner toward the right side.
[0038] FIG. 2B shows states of the user's own vehicle 80 and the
other vehicle 90 at the moment of a collision (TTC=0). FIG. 2C
shows states of the user's own vehicle 80 and the other vehicle 90
immediately after the collision has occurred. At the moment of the
collision and immediately after the collision has occurred, the
brake control unit 40 maintains the operating state of the brake
system 18 prior to the collision (see FIG. 2A). As a result, the
braked state of the right wheels 84R is maintained.
[0039] FIG. 2D shows states of the user's own vehicle 80 and the
other vehicle 90 after the collision (following an elapse of time
immediately after the collision has occurred). FIG. 2E shows a
state of the user's own vehicle 80 following a further elapse of
time after the point in time shown in FIG. 2D. After the collision,
the brake control unit 40 controls the operating state of the brake
system 18 depending on the roll direction. More specifically, in
the case that the roll direction is a direction of turning to the
left, the brake control unit 40 makes the braking force of the
brakes on the left side stronger than the braking force of the
brakes on the right side. Upon doing so, as shown in FIG. 2D, the
left wheels 84L are subjected to braking. On the other hand, in the
case that the roll direction is a direction of turning to the
right, the brake control unit 40 makes the braking force of the
brakes on the right side stronger than the braking force of the
brakes on the left side. Upon doing so, as shown in FIG. 2E, the
right wheels 84R are subjected to braking.
[0040] FIG. 2F shows a state in which the user's own vehicle 80 is
stopped at a point in time after the point in time shown in FIG.
2E. The brake control unit 40 locks all of the brakes. Upon doing
so, the left wheels 84L and the right wheels 84R are stopped. At
this time, the brake control unit 40 may also cause the parking
brake to be operated.
2.2. Situation in which Other Vehicle 90 Having a Higher Vehicle
Height Collides with Side Surface 82 of User's Own Vehicle 80
[0041] In the case that the vehicle height of the other vehicle 90
is higher than the vehicle height of the user's own vehicle 80, the
brake control unit 40 causes the operating state of the brakes to
undergo a transition as shown in FIGS. 3A to 3F. Moreover, in the
description given below, weakening of the braking force of the
brakes also includes releasing of the brakes.
[0042] FIG. 3A shows states of the user's own vehicle 80 and the
other vehicle 90 when the TTC has become less than or equal to the
predetermined control starting time period. At this time, the brake
control unit 40 generates a braking force for the brakes on the
left side, which is the non-collision side, in particular, the left
front brake unit 46LF and the left rear brake unit 46LR. Upon doing
so, the left wheels 84L are subjected to braking. At this time, the
brake control unit 40 may generate a braking force for the brakes
on the right side, which is the collision side, in particular, the
right front brake unit 46RF and the right rear brake unit 46RR.
However, in the case that the braking force of the brakes on the
right side is generated, the brake control unit 40 makes the
braking force of the brakes on the right side weaker than the
braking force of the brakes on the left side. Due to the control
performed by the brake control unit 40, the user's own vehicle 80
becomes inclined in a sunken-in manner toward the left side.
[0043] FIG. 3B shows states of the user's own vehicle 80 and the
other vehicle 90 at the moment of a collision (TTC=0). FIG. 3C
shows states of the user's own vehicle 80 and the other vehicle 90
immediately after the collision has occurred. At the moment of the
collision and immediately after the collision has occurred, the
brake control unit 40 maintains the operating state of the brake
system 18 prior to the collision (see FIG. 3A). As a result, the
braked state of the left wheels 84L is maintained.
[0044] FIG. 3D shows states of the user's own vehicle 80 and the
other vehicle 90 after the collision (following an elapse of time
immediately after the collision has occurred). FIG. 3E shows a
state of the user's own vehicle 80 following a further elapse of
time after the point in time shown in FIG. 3D. FIG. 3F shows a
state in which the user's own vehicle 80 is stopped at a point in
time after the point in time shown in FIG. 3E. The brake control
from after the collision until the user's own vehicle 80 comes to a
stop is the same as the brake control that was described in [2.1]
above with reference to FIGS. 2D to 2F.
2.3. Vehicle Behavior Control Process
[0045] When the ON/OFF switch 12 is turned ON, the process
described below is initiated. Further, when the ON/OFF switch 12 is
turned OFF, the process described below is terminated.
[0046] In step S1 of FIG. 4, the collision prediction unit 36
determines whether or not there is a possibility that a side
collision will occur. For example, the other vehicle detection unit
34 and the collision prediction unit 36 perform the following
processes. The other vehicle detection unit 34 detects the other
vehicle 90 on the basis of the image information. Based on the
image information over a predetermined period of time, the
collision prediction unit 36 obtains the travel locus of the other
vehicle 90 up to the present time and the travel speed of the other
vehicle 90 at the present time. Furthermore, based on the travel
locus and the travel speed of the other vehicle 90, the collision
prediction unit 36 predicts a planned travel position (planned
travel trajectory) and a planned travel time for the other vehicle
90. Further, the collision prediction unit 36 predicts a planned
travel position (planned travel trajectory) and a planned travel
time for the user's own vehicle 80, based on the steering angle
measured by the steering angle sensor 27 and the wheel speeds
measured by the wheel speed sensors 26. In the case that a position
exists that coincides with the planned travel position of the
user's own vehicle 80 and the planned travel position of the other
vehicle 90, and further, the planned travel time of the other
vehicle 90 is later than the planned travel time of the user's own
vehicle 80 at that position by only a slight or negligible amount
of time, the collision prediction unit 36 determines that there is
a possibility that a side collision may occur. The collision
prediction unit 36 sets the position as a planned collision site.
Further, the collision prediction unit 36 predicts the direction
(the side of the collision) in which the side collision occurs. If
there is a possibility that a side collision may occur (step S1:
YES), the process transitions to step S2. On the other hand, if
there is not a possibility that a side collision will occur (step
S1: NO), the process of step S1 is repeatedly executed.
[0047] In step S2, the physical quantity determination unit 38
estimates the vehicle height of the other vehicle 90 on the basis
of the image information. The physical quantity determination unit
38 may recognize an outer shape of the other vehicle 90 based on
the image information, and calculate the vehicle height from the
outer shape. Alternatively, the physical quantity determination
unit 38 may recognize the external appearance of the other vehicle
90 based on the image information, and may obtain, from the vehicle
information stored in the storage unit 32, the vehicle height for a
type of vehicle that matches the external appearance. Upon
completion of step S2, the process transitions to step S3.
[0048] In step S3, the collision prediction unit 36 calculates a
time period until reaching the planned collision site, based on the
relative speed between the user's own vehicle 80 and the other
vehicle 90, and the inter-vehicular distance between the vehicles.
This time period corresponds to the TTC. Upon completion of step
S3, the process transitions to step S4.
[0049] In step S4, the collision prediction unit 36 compares the
TTC with the predetermined control starting time period. The
control starting time period is a time period to a timing at which
the behavior control by brake control is started, and is stored in
advance in the storage unit 32. In the case that the TTC is less
than or equal to the control starting time period (step S4: YES),
the process transitions to step S5. On the other hand, in the case
that the TTC is greater than the control starting time period (step
S4: NO), the process of step S4 is repeatedly executed.
[0050] In step S5, using the vehicle information stored in the
storage unit 32 and the result of the estimation made in step S2,
the physical quantity determination unit 38 compares the vehicle
height of the user's own vehicle 80 and the vehicle height of the
other vehicle 90. In the case that the vehicle height of the user's
own vehicle 80 is greater than or equal to the vehicle height of
the other vehicle 90 (step S5: YES), the process transitions to
step S6. On the other hand, in the case that the vehicle height of
the user's own vehicle 80 is less than the vehicle height of the
other vehicle 90 (step S5: NO), the process transitions to step
S7.
[0051] In step S6, the brake control unit 40 operates the brakes on
the side of the collision. At this time, as shown in FIG. 2A, the
user's own vehicle 80 is inclined in a sunken-in manner on the side
of the collision (the right side in FIG. 2A). Upon completion of
step S6, the process transitions to step S8.
[0052] In step S7, the brake control unit 40 operates the brakes on
the side where the collision does not take place. At this time, as
shown in FIG. 3A, the user's own vehicle 80 is inclined in a
sunken-in manner on the side where the collision does not take
place (the left side in FIG. 3A). Upon completion of step S7, the
process transitions to step S8.
[0053] In step S8, the collision detection unit 42 determines
whether or not a side collision has occurred. As shown in FIGS. 2C
and 3C, immediately after the side collision has occurred, in the
user's own vehicle 80, an acceleration which is particular to a
side collision is generated in each of the axial directions. The
collision detection unit 42 determines that the side collision has
occurred, in the case that the acceleration in each of the axial
directions as measured by the acceleration sensor 24 indicates an
acceleration particular to a side collision. In the case that a
side collision has occurred (step S8: YES), the process transitions
to step S9. On the other hand, in the case that a side collision
has not occurred (step S8: NO), the process of step S8 is
repeatedly executed. At this time, the operating states of the
brakes are maintained.
[0054] In step S9, the posture determination unit 44 determines
whether or not the roll direction has changed. Immediately after
the side collision, the user's own vehicle 80 rolls in a
non-collision direction (i.e., the direction of the side where the
collision did not take place) (see FIGS. 2C to 2D and FIGS. 3C to
3D). Thereafter, the roll direction undergoes a change, and the
user's own vehicle 80 rolls in the direction of the collision (see
FIGS. 2D to 2E and FIGS. 3D to 3E). Furthermore, thereafter, there
may be cases in which the roll direction changes once or more than
once. The posture determination unit 44 detects such a change in
the roll direction, based on an acceleration of the roll axis as
measured by the acceleration sensor 24. In the case that the roll
direction has changed (step S9: YES), the process transitions to
step S10. On the other hand, in the case that the roll direction
has not changed (step S9: NO), the process transitions to step
S11.
[0055] In step S10, the brake control unit 40 switches the
strength/weakness of the left and right brakes. For example, in the
case that the roll direction has changed from the non-collision
side to the collision side, the brake control unit 40 strengthens
the braking force of the brakes on the collision side, and weakens
the braking force of the brakes on the non-collision side. As a
result, the braking force of the brakes on the collision side
becomes stronger than the braking force of the brakes on the
non-collision side (a transition takes place from the state shown
in FIG. 2D to the state shown in FIG. 2E and a transition takes
place from the state shown in FIG. 3D to the state shown in FIG.
3E). For example, in the case that the roll direction has changed
from the collision side to the non-collision side, the brake
control unit 40 strengthens the braking force of the brakes on the
non-collision side, and weakens the braking force of the brakes on
the collision side. As a result, the braking force of the brakes on
the non-collision side becomes stronger than the braking force of
the brakes on the collision side (a transition takes place from the
state shown in FIG. 2E to the state shown in FIG. 2D and a
transition takes place from the state shown in FIG. 3E to the state
shown in FIG. 3D).
[0056] In step S11, the posture determination unit 44 determines
whether or not the user's own vehicle 80 has come to a stop. The
posture determination unit 44 determines that the user's own
vehicle 80 has come to a stop, in the case that the acceleration in
each of the axial directions measured by the acceleration sensor 24
has become zero. In the case that the user's own vehicle 80 has
come to a stop (step S11: YES), the process transitions to step
S12. On the other hand, in the case that the user's own vehicle 80
has not come to a stop (step S11: NO), the process returns to step
S9.
[0057] In step S12, the brake control unit 40 locks all of the
brakes. The above step completes the series of vehicle behavior
control processes.
2. Second Embodiment
[0058] As shown in FIG. 5, the vehicle behavior control device 10
according to the second embodiment is further equipped with a
weight sensor 94 in addition to each of the constituent elements of
the vehicle behavior control device 10 according to the first
embodiment. The weight sensor 94 measures the weight of the user's
own vehicle 80 other than the weight of the vehicle body. For
example, as the weight sensor 94, there can be used seat sensors
that measure the weight of each of the vehicle occupants, a stroke
sensor that measures an amount of sinkage of the suspension, or the
like. The weight sensor 94 outputs information of the measured
weight to the brake ECU 16.
[0059] Based on the weight information output by the weight sensor
94, the computation unit 30 changes the timing at which switching
of the strength/weakness of the left and right brakes takes place,
and the time period for which the brakes are operated. For example,
the storage unit 32 stores a map 96 that associates the weights
with delay time periods. The brake control unit 40 obtains from the
map 96 the delay time period in accordance with the weight. In
addition, in step S10 of FIG. 4, the brake control unit 40 switches
the strength/weakness of the left and right brakes, after the delay
time period has elapsed from the roll direction having been
changed. Similarly, the brake control unit 40 may determine the
time period for which the brakes are operated in accordance with
the weight.
3. Other Examples
[0060] The vehicle behavior control device 10 may include a
positioning device such as a GPS, a steering angle sensor, or the
like. In this case, the collision prediction unit 36 may predict
the planned travel position and the planned travel time period for
the user's own vehicle 80 using the positioning device such as the
GPS, the steering angle sensor, or the like.
[0061] The vehicle behavior control device 10 may include a
communication device that performs inter-vehicle communications
with the other vehicle 90. In this case, the collision prediction
unit 36 may acquire information such as the travel locus, the
planned travel trajectory, the travel speed, and the like from the
other vehicle 90 by way of inter-vehicle communications.
[0062] The physical quantity determination unit 38 may utilize as
the physical quantities information concerning the height of a
center of gravity of the user's own vehicle 80, and information
concerning the position of the collision (for example, the height
position of a front end) of the other vehicle 90. Further, the
physical quantity determination unit 38 may utilize as the physical
quantities information concerning the body types of the user's own
vehicle 80 and the other vehicle 90.
4. Technical Concepts Obtained from the Embodiments
[0063] Technical concepts that can be grasped from the
above-described embodiments will be described below.
[0064] The first aspect of the present invention is characterized
by the vehicle behavior control device 10 that controls the
behavior of the user's own vehicle 80 when the other vehicle 90 is
predicted to collide with the side surface 82 of the user's own
vehicle 80, the vehicle behavior control device comprising:
[0065] the other vehicle detection unit 34 that detects the other
vehicle 90;
[0066] the collision prediction unit 36 which predicts that the
other vehicle 90 will collide with the side surface 82 of the
user's own vehicle 80;
[0067] the physical quantity determination unit 38 that determines
the physical quantity relationship between the relative physical
quantities of the other vehicle 90 and the user's own vehicle 80;
and
[0068] the brake control unit 40 which is capable of individually
and independently controlling the brakes (the right front brake
unit 46RF, the right rear brake unit 46RR, the left front brake
unit 46LF, and the left rear brake unit 46LR) corresponding to the
respective vehicle wheels (the right wheels 84R and the left wheels
84L), and which causes the braking force of the brakes on the
collision side and the braking force of the brakes on the
non-collision side to differ from each other, in accordance with
the physical quantity relationship determined by the physical
quantity determination unit 38, in the case that the collision is
predicted by the collision prediction unit 36.
[0069] When the braking force of the brakes on the collision side
and the non-collision side are made to differ from each other, as
in the above-described configuration, one of the braking forces
becomes stronger than the other braking force, and a variation in
the roll direction of the user's own vehicle 80 becomes smaller.
Therefore, in accordance with the above-described configuration,
the behavior of the user's own vehicle 80 in the roll direction can
be stabilized. Further, the control in which the braking force of
the brakes on the collision side and the braking force of the
brakes on the non-collision side are made to differ in accordance
with the physical quantity relationship between the relative
physical quantities of the other vehicle 90 and the user's own
vehicle 80 is a simpler control as compared with a precise control
for each of the vehicle wheels. Consequently, according to the
above-described configuration, with a simple control, it is
possible to stabilize the behavior of the user's own vehicle 80 in
the roll direction, in the case that the other vehicle 90 collides
with the side surface 82 of the user's own vehicle 80.
[0070] In the first aspect,
[0071] the collision prediction unit 36 may predict the time of the
collision of the other vehicle 90 with the side surface 82 of the
user's own vehicle 80; and
[0072] in the case that the physical quantity determination unit 38
determines that the physical quantity of the other vehicle 90 is
less than the physical quantity of the user's own vehicle 80, the
brake control unit 40 may make the braking force of the brakes (the
right front brake unit 46RF and the right rear brake unit 46RR) on
the collision side greater than the braking force of the brakes
(the left front brake unit 46LF and the left rear brake unit 46LR)
on the non-collision side at a predetermined time (control starting
time period) prior to the time of the collision, and may make the
braking force of the brakes on the non-collision side greater than
the braking force of the brakes on the collision side after the
collision.
[0073] In accordance with the above-described configuration, since
the brake control is performed prior to the collision, the behavior
of the user's own vehicle 80 in the roll direction can be made more
stable.
[0074] In the first aspect,
[0075] the collision prediction unit 36 may predict the time of the
collision of the other vehicle 90 with the side surface 82 of the
user's own vehicle 80; and
[0076] in the case that the physical quantity determination unit 38
determines that the physical quantity of the other vehicle 90 is
greater than the physical quantity of the user's own vehicle 80,
the brake control unit 40 may make the braking force of the brakes
(the left front brake unit 46LF and the left rear brake unit 46LR)
on the non-collision side greater than the braking force of the
brakes (the right front brake unit 46RF and the right rear brake
unit 46RR) on the collision side at a predetermined time (control
starting time period) prior to the time of the collision.
[0077] In accordance with the above-described configuration, since
the brake control is performed prior to the collision, the behavior
of the user's own vehicle 80 in the roll direction can be made more
stable. Further, in accordance with the above-described
configuration, since the impact of the collision can be absorbed by
the surface, the behavior of the user's own vehicle 80 in the roll
direction can be made more stable.
[0078] In the first aspect,
[0079] there may further be provided the posture determination unit
44 that determines the posture of the user's own vehicle 80;
[0080] wherein, after the collision, the brake control unit 40 may
perform a control to cause the braking force of the brakes on the
collision side and the braking force of the brakes on the
non-collision side to differ from each other, and thereafter, may
switch a strength of the braking force of the brakes between the
collision side and the non-collision side in accordance with the
posture of the user's own vehicle 80 determined by the posture
determination unit 44.
[0081] In accordance with the above-described configuration, since
the strength/weakness of the brakes are switched after the
collision, the behavior of the user's own vehicle 80 in the roll
direction can be made more stable.
[0082] The second aspect of the present invention is characterized
by the vehicle behavior control method of controlling, using a
processor (computation unit 30), the behavior of the user's own
vehicle 80 when the other vehicle 90 is predicted to collide with
the side surface 82 of the user's own vehicle 80, wherein the
brakes (the right front brake unit 46RF, the right rear brake unit
46RR, the left front brake unit 46LF, and the left rear brake unit
46LR) corresponding to the respective vehicle wheels (the right
wheels 84R and the left wheels 84L) are capable of being
individually and independently controlled,
[0083] the vehicle behavior control method comprising:
[0084] the other vehicle detecting step (step S1) of detecting the
other vehicle 90;
[0085] the collision predicting step (step S1) of predicting that
the other vehicle 90 will collide with the side surface 82 of the
user's own vehicle 80;
[0086] the physical quantity determination step (step S2) of
determining the physical quantity relationship between the relative
physical quantities of the other vehicle 90 and the user's own
vehicle 80; and
[0087] the brake controlling step (step S6, step S7) of causing the
braking force of the brakes on the collision side and the braking
force of the brakes on the non-collision side to differ from each
other, in accordance with the physical quantity relationship
determined in the physical quantity determination step, in the case
that the collision is predicted in the collision predicting
step.
[0088] The vehicle behavior control device and the vehicle behavior
control method according to the present invention are not limited
to the embodiments described above, and it is a matter of course
that various modified or additional configurations could be adopted
therein without deviating from the essence and gist of the present
invention.
* * * * *